LED Strip Power Supply Calculator
Total wattage, current and recommended power supply size for a run of LED strip.
Results
Power
72.00
W
Current
6.000
A
Recommended power supply
86.4
W
Conductor cross-section
1.167
mm²
What this tool does
Low-voltage strip draws a surprising amount of current: five metres of 14.4 W/m at 12 V pulls six amps, which is why thin feed wires get warm and the far end looks dimmer. The last figure is the copper cross-section needed to keep the drop at 3 % over a two-metre feed.
Formula
P = W/m × length , I = P ÷ U
Variables
| Symbol | Meaning | Unit |
|---|---|---|
wm | Power per metre | W/m |
l | Strip length | m |
u | Voltage | V |
m | Percentage | % |
P | Power | W |
I | Current | A |
PS | Recommended power supply | W |
S | Conductor cross-section | mm² |
Worked example
- Power per metre14.4 W/m
- Strip length5 m
- Voltage12 V
- Percentage20 %
- Power72.00 W
- Current6.000 A
- Recommended power supply86.4 W
- Conductor cross-section1.167 mm²
Limitations
- Electrical installations are governed by national wiring rules. Cable sizing also depends on installation method, grouping, ambient temperature and protection devices, which this calculator does not evaluate.
- The result is an estimate based only on the values you type. Real situations often include factors this calculator does not know about.